You've got the right idea. Work on your approach on a basic level. There's good lessons available on the Web. Check out Pete Emslie. He was on AN years ago. He has instructional videos on YouTube that'll help you grow.

In general you're on the right track. Let me pose this question to you. If you were at Pixar and these drawings were a job you had to do, would you be comfortable showing them to John Lasseter?

Take your time. Finish each drawing. Bring it to a sense of completion. Be thorough and professional. Frankly this would not fly in my class. It would not be acceptable work. Spend more time on each sketch without leaving it looking like it's half done. That's the main thing ya gotta do. Bring it on home and finish it. Hope you can appreciate my comments, they're meant to encourage.

Iron Duck drawing is looking okay but again... Where's the construction and your attention to fundamentals. You're not taking the time you need to get this right. Look at the lettering for example. Would you show this to Lasseter if you worked for him?

Look at how Pete Emslie is drawing in the videos above and thoroughly emulate that approach in your work.

Discipline yourself to incorporate basic fundamentals into your work and strive to be professional in the presentation of your art. You'll improve faster, your skills will get stronger and you'll attract peers and develop fans.